1. Field
The invention is in the field of musculoskeletal testing, particularly the field of muscle strength testing referred to sometimes as Manual Muscle Testing and Computerized Muscle Testing, in range of motion testing, and in tender point evaluation, particularly on human patients.
2. State of the Art
Several instruments are currently available for use by physical therapists, orthopedic surgeons, neurologists, and chiropractors for measuring muscle strength (Manual Muscle Testing or Computerized Muscle Testing) and performing tender point evaluation in human patients. Instruments are also available for measuring range of motion of various body parts in human patients.
Muscle strength testing is used to identify areas of muscular weakness due to injury or disease. The results provide clinicians with valuable information for diagnosis of extent of injury and disability. Range of motion testing provides information as to limitations in movement of body parts such as the back and neck and again provides valuable information for diagnosis of extent of injury and disability. The information may be used to complete and calculate disability ratings and indexes, and compares activities of daily living questionnaires such as the Oswestry Low Back, Neck Pain, Rand 36, and Roland Morris questionnaires. Tender point (algometry) evaluation indicates whether a patient is a candidate for the diagnosis of fibromyalgia pursuant to the American College of Rheumatology standards.
U.S. Pat. No. 5,090,421, issued to one of the inventors hereof and assigned to the assignee of the present invention, describes an apparatus for testing muscle strength which is used extensively for muscle strength testing. It is also used for tender point evaluation. Range of motion testing instruments are also available. There are also several computer programs available for recording the results of such testing and producing reports based on such results. However, separate instruments are used to measure muscle strength and range of motion and where both types of measurements are being taken, as is common in many situations, the person doing the testing must set up the instrument for one type of testing, perform those tests, and then set up the other instrument for and perform the other type of testing. Where the instruments are connected to a computer, one instrument is coupled to the computer and the measurements taken and then the other instrument is coupled to the computer and measurements taken. This extends the time for patient testing, increasing patient discomfort, and increasing the cost both because of the increased time and because of the requirement for two sets of testing equipment.
According to the invention, the same apparatus is used for both muscle strength testing and range of motion testing. While different sensors are used for each type of measurement in the apparatus, a single microprocessor and the same data transmission circuits are used for determining and reporting the results of such testing.
The apparatus of the invention includes a housing, preferably an ergonomically designed housing sized and configured to easily fit into and be held by a user""s hand and having an indentation aligned with the user""s thumb when the housing is properly held by a user for range of motion testing. A push button switch is located in the indentation to be thumb operated by the user when a range of motion measurement is desired to be made. While a particular configuration of apparatus is shown in the drawings with a particular configuration of thumb indentation, various configurations and various configurations of thumb indentations can be used and the particular configuration is not critical. The particular configuration shown is used for aesthetic reasons. The housing includes at least one contact area for aligning the housing with a portion of a patient""s body. This at least one contact area is preferably two spaced apart contact areas positioned on a portion of the housing that extends from a user""s hand when properly held in the user""s hand for range of motion testing. The contact areas may include a nonslip surface. Within the housing is an inclinometer to measure the angle of the device and produce an angle signal indicative of the measured angle. The range of motion of a body part is determined by measuring the angle of the part at one extreme of movement and measuring the angle of the same part at the other extreme of movement. The difference of the two measurements indicates the range of motion of the body part.
A force applicator coupler removably secures a force applicator to a force transducer which measures the force applied to the transducer by the applicator and produces a force signal indicative of the force applied. The force applicator is positioned against a body part of the patient being tested and force is applied between the patient""s body part and the apparatus. Where the force applied is caused by the muscles of the patient, the force applied is a measure of muscle strength. Various force applicators with differing surface configurations may be selectively used for different parts of the body.
Interface circuitry converts the angle signals and the force signals into usable output signals indicative of range of motion or muscle strength. Such usable signals can generate a display of a measurement of range of motion or muscle strength such as on an LCD display included as part of the apparatus and/or may provide signals to a computer for use in a computer program which displays and/or prints out measurements, stores and compares measurements and/or provides reports of measurements and differences in measurements over time, graphs such comparisons of measurements, etc.
The apparatus may be connected by a cable to a computer during taking of measurements, or may transmit measurements during taking of measurements by wireless transmission such as by RF transmission, infrared light transmission, or any other suitable wireless transmission.